Fluidic pulse generator



Dec. 16, 1969 R, B. HARTMAN FLUIDIG PULSE GENERATOR Filed July 6, 1967 1 3 n% mm m v 0 ma Wm Q mm United States Patent 3,483,883 FLUIDIC PULSE GENERATOR Robert B. Hartman, Bridgeport, Conn., assignor to Remington Arms Company, Inc., Bridgeport, Conn., a c rporation of Delaware Filed July 6, 1967, Ser. No. 651,550 Int. Cl. F15c 3/06 U.S-. Cl. 137-815 7 Claims ABSTRACT OF THE DISCLOSURE A fiuidic pulse generator having a movable member in a channel, the movable member and channel being arranged so that the movable member is held normally in arest position at one end thereof by gravity or other retaining means, an input fluid pressure connection to said channel adjacent the rest position of the movable member, there being an output signal passage adjacent the input connection. The channel has a venting means near the portion remote from the rest position thereof so that upon application of input pressure, the movable member will travel until the vent passage or area is reached, a pulse being generated of desired shape during this portion of the operation. The movable member has an effective mass which permits the back-pressure signal to be created during its travel past the vent.

This invention relates to fiuidic pulse generators.

In some types of fiuidic operated devices, a pulse is utilized which must be carefully controlled with certain limits. As an example, in the memory device as shown in copending application Ser. No. 629,254 filed Apr. 7, 1967, the movable member must be given a pulse of sufficient length to carry it beyond the bistable center from a first bistable position so that it will carry over to its second stable position, but no so long as to prevent the movable element from reaching its second position by the pulse from the opposite input.

One of the objects of the invention is to provide a fiuidic pulse generator which will generate a pulse with a predetermined pulse width.

In one aspect of the invention, a channel receiving a movable member is arranged so that the movable member normally is held at one end thereof by gravity. An input passage is connected to said channel under said movable member and an output signal passage is connected thereto. The upper end of said channel has a vent arrangement or is constructed so that there will be a relatively abrupt change in pressure in said channel when the movable member reaches a predetermined point in the upward travel in the channel. When pressure is applied under the movable member, it will start to move upward or away from its normal position. There will be a back pressure developed in the signal output passage and the back pressure will continue until the movable member has reached a predetermined point and the input pressure is released through the vent arrangement.

These and other features, objects and advantages of the invention will become apparent from the following description and drawings.

In the drawings:

FIG. 1 is a perspective view of one form of the invention.

FIG. 2 is an enlarged schematic sectional elevation of the form of the invention illustrated in FIG. 1.

FIG. 3 is a graph illustrating the pulse shape formed by FIG. 2, the graph showing relation between pressure and time.

FIG. 4 is an enlarged schematic sectional elevation of a different embodiment of the invention of FIG. 1.

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FIG. 5 is a graph illustrating the pulse shape formed by FIG. 4, the graph showing the relation between pressure and time.

Referring to FIG. 1, the devices can be made of plates 9, 10 made of a suitable material such as a plastic. The plates can be cemented Or suitably fastened together.

Plate 10 (FIG. 2) has channel 11 formed therein. Input passage 12 can be connected to a controlled source of fluid pressure. Output signal passage 13 is connected to the device to which a pulse is to be provided. These passages communicate with openings 12A and 128 (FIG. 1).

Movable member 14 can be a fiat disc of suitable material. It also could be of a suitable fluid. At the top of channel 11 there is located a vent 15 communicating with 15A (FIG. 1), with passages 16, 17 connecting the same to channel 11.

Upon application of input pressure to passage 12, movable member 14 will start upwardly. A back pressure will be created in passage 13 to provide the step 18 (FIG. 3) of the pulse. When the movable member 14 reaches the upper portion of its travel and the input pressure is released through vent 15, through passage 17, the portion 19 of the pulse will 'be produced. Step 19A of the graph represents that pressure which is required to sustain the movable element in the upper position.

The size and weight of the movable member must be correlated with the input pulse or flow and channel lengths so as to obtain the desired pulse amplitude and length. Also, the channel could be inclined.

Another form of the generator is shown in FIG. 4 wherein support or plate 20 has channel 21 therein with input passage 22 and signal output passage 23 connected to channel 21 under the movable member 24. Enlarged portion 25 has a large vent 26 therein. The surface of enlarged portion or chamber 25 is shaped so that the movable member will travel along curved portion 25A and inclined portion 27 before returning to channel 21. When the movable member again reaches channel 21, if the input pressure is continuing, only that pressure required to prevent the element from rolling from 27 incline to channel 21 is reflected in the output signal.

Step 28 of the pulse (FIG. 5) will occur as the movable member travels upwardly in channel 21. When it passes inclined surface 27, step 29 will occur. With the proper relative position of input passage 22 to output passage 23, venting action can cause negative pressure at the output as illustrated at 29A.

Also, the movable member 14 or 24 can be of a magnetic material and a magnet 30 (FIG. 2) can be placed adjacent or in contact with the walls of the inactive position shown in FIGS. 2, 4 so as to cause the movable member to return thereto after the signal input pressure has ceased or has been sufficiently reduced. In such an arrangement, the device can be operated in other than a near vertical position.

What is claimed is:

1. In a fiuidic pulse generator, the combination including a support means having a channel therein, a movable member in said channel normally urged to and retained at a stable position at a first end of said channel, signal input means connected to said channel at said first end thereof, vent means for said channel on the opposite side of said movable means, and an output pressure connection adjacent said signal input means and said first end of said channel on the same side of the movable member, said channel and movable member being sized relative to each other so that said movable member moves a predetermined distance before said input pressure is released by venting through said vent means, said movable member then returning to said stable position, so as to provide a pulse of a predetermined shape.

2. A device according to claim 1 wherein the signal input and output pressure means are angularly disposed relative to each other.

3. A device according to claim 1 having a magnetic means adjacent said normal stable position.

4. A device according to claim 1 wherein at the end of said channel opposite to said first end there is a chamber into which the signal input pressure passes to said vent means after said movable member has reached said chamber configuration.

5. A device according to claim 4 wherein the chamber has an upper curved wall around which said movable member moves before returning to said channel.

6. A device according to claim 4 wherein said chamber has at least a pair of passages, the walls therebetween retaining said movable member in said device, said passages leading to said vent means.

7. A device according to claim 4 wherein the vent passage is connected to the chamber. 3

References Cited UNITED STATES PATENTS 3,151,623 10/ 1964 Riordan.

3,168,898 2/1965 Samet.

3,202,179 8/1965 Vockroth.

3,318,329 5/1967 Norwood.

3,334,644 8/ 1967 Williamson.

3,357,638 12/1967 Sher et a1.

3,362,633 1/1968 Freeman.

SAMUEL SCOTT, Primary Examiner US. Cl. X.R. 

